This application is based on Application No. 2000-374322, filed in Japan on Dec. 8, 2000, the contents of which are hereby incorporated by reference.
This invention relates to an apparatus for electrically operating a circuit breaker and, more particularly, to an apparatus for switching an operating handle of a circuit breaker by electrical or manual operation.
A circuit breaker, which is a device for interrupting a fault current such as a short-circuiting current flowing through an electrical circuit as an overcurrent, is equipped with an electrically operating apparatus which achieves the circuit interruption.
An example of the apparatus for electrically operating a circuit breaker of such type can be found in Japanese Patent Laid-Open No. 6-251687 (or U.S. Pat. No. 5,504,290) and is shown in FIGS. 8 and 9. In FIGS. 8 and 9, the reference numeral 1 is an electrically operating apparatus including a drive motor 2, 3 is a change-over lever for shifting between a manual operation mode and an electrical operation mode, the switching of the change-over switch 4 can be achieved by sliding the change-over lever 3 into the direction of an arrow B1 or an arrow B2 (to the left or right in FIG. 8). That is, when the change-over lever 3 is slid in the direction of the arrow B2 to change the mode into the electrical operation mode, an electric current is supplied to the drive motor 2 and when the change-over lever 3 is slid in the direction of the arrow B1 to change the mode into the manual operation mode, no current is supplied to the drive motor 2.
The reference numeral 5 is a manual operation handle for manually opening the circuit breaker, 6 is an ON button for closing the circuit breaker, 7 is a TRIP button for opening the circuit breaker, 8 is a main shaft for transmitting the operational force from the drive motor 2 and the manual operation handle 5, 9 are cams mounted on the main shaft 8, 10 are drive levers for transmitting a drive force on the main shaft 8 through the cams 9, 11 are rollers rotatably mounted to the drive levers 10 and brought into contact with the cams 9, 13 is an actuating pin secured to the drive levers 9 and 12 is an operation handle engaging the actuating pin 13.
In the conventional apparatus as above described, when the change-over lever 3 is slid in the direction of the arrow B1, the change-over switch 4 is opened and the manual operation mode is established.
When the manual operation handle 5 is moved up and down as shown in an arrow C in FIG. 8, the main shaft 8 rotates. Then, the drive levers 10 are rotated through the cams 9 and the actuating pin 13 causes the operation handle 12 to operate to open the circuit breaker. When the ON button 6 is depressed, the circuit breaker is closed by the action of the energy charging spring (not shown) which is charged by the rollers 11 during the rotation of the drive levers 10. When the TRIP button 7 is depressed, the trip device (not shown) initiates the trip operation (same as the operation due to an overcurrent) and the circuit breaker is opened.
On the other hand, when the change-over lever 3 is slid into the arrow B2, the change-over switch 4 is closed to establish the electrical operation mode. In this mode, the circuit breaker can be opened or closed by energizing the drive motor 2 by remote control to rotate the main shaft 8. When the change-over lever 3 is slid in the direction of the arrow B2, the change-over lever 3 engages with an engagement portion 6a disposed on the ON button 6 and an engagement portion 7a disposed on the TRIP button 7. Therefore, the ON button 6 and the TRIP button 7 are prevented from moving further by the change-over lever 3. On the other hand, the manual operation handle 5 does not have any structure that is restricted by the change-over lever 3, so that the manual operation handle 5 is in the state in which it can be freely operated.
In such the conventional apparatus for electrically operating a circuit breaker, the manual operation handle 5 is not prevented from moving by the change-over lever 5 even when the circuit breaker is being remote controlled by the drive force of the drive motor 2 in the electrical operation mode, so that the manual operation handle 5 can be moved, whereby the drive motor 2 constituting the electrical operating apparatus 1 is locked and may be damaged.
Accordingly, the chief object of the present invention is to provide an apparatus for electrically operating a circuit breaker free from the above discussed problems of the conventional apparatus.
Another object of the present invention is to provide an apparatus for electrically operating a circuit breaker in which not only the ON button and the TRIP button but also the manual operation handle can be prevented from being moved during the electrical operation mode, whereby the electrical operation apparatus is not damaged and a reliable operation can be ensured.
With the above objects in view, the present invention resides in an apparatus for electrically operating a circuit breaker, in which a control panel on a housing of the circuit breaker is provided therein a change-over lever for selectively changing between an electrical operation mode and a manual operation mode, and in which the circuit breaker is operated between the open and closed positions by a drive force from a drive motor during the electrical operation mode and the circuit breaker is operated between the open and closed positions by a drive force from a manual operation handle during the manual operation mode. The apparatus is arranged such that the change-over lever moves between an electrical operation mode position corresponding to the electrical operation mode and a manual operation mode position corresponding to the manual operation mode, and that the change-over lever has provided therewith a blocking portion which, while allowing the operation of the manual operation handle when the change-over lever is in the manual operation mode position, engages the manual operation handle to prevent the operation of the manual operation handle when the change-over lever is at the electrical operation mode position.
The control panel may comprise an ON button for closing the circuit breaker in the manual operation mode and a TRIP button for opening the circuit breaker in the manual operation mode, and the change-over lever may be provided with a first engagement portion and a second engagement portion engaging the ON button and the TRIP button to prevent the operations of the ON button and the TRIP button when the change-over lever is shifted into the electrical operation mode.
The change-over lever may have the blocking portion, the first engagement portion and the second engagement portion provided thereon as an integral and unitary structure.
Alternatively, apparatus for electrically operating a circuit breaker may further comprise a switch disposed in the vicinity of the change-over lever for controlling electric current supply to the drive motor in response to the position of the change-over lever, the switch supplying the current to the drive motor when the change-over lever is in the electrical operation mode position and supplying no current to the drive motor when the change-over lever is in the manual operation mode.
The manual operation handle may comprise a first link mounted to an energy charging means actuating shaft for actuating energy charging means, a second link pivotally connected to the first link and a spring for biasing the second link toward the position in which the second link is housed within the housing of the electrically operating apparatus, and the arrangement may be such that, when the manual operation handle is operated, the first link is rotated over a first rotation range in which the first link is rotated against the action of the spring until it engages with the second link as well as a second rotation range in which the first link, together with the second link, drives the energy charging means actuating shaft.